54 GENERAL HISTORY OF 



vesicles and nucleus (testis), and would assign to the former, a cardiac 

 or circulatory function. 



S])ontancous Generation. — The Infusoria were, veiy generally, con- 

 sidered to have a yeneratio primitiva, or, in other words, to be 

 produced by some fortuitous combination of circumstances from in- 

 organic matter. That such a statement is untenable, most persona 

 will be inclined to admit, who have perused the descriptions con- 

 tained in the Third Part of this work. All the obsen'ations that can 

 be depended upon, tend to show that infusions of vegetable or 

 animal matters, whether natiu-al or artificial, only offer food for the 

 nourishment of these living atoms, whose germs are almost eveiy- 

 where present, but are only developed in situations congenial to 

 their natm-es. It is now well ascertained that the old notions of 

 certain vegetable infusions producing a definite species of Infusoria, 

 is an eiTor ; that, in general, we have, in all artificial infusions, only 

 common species, and that these invariably making theii' appearance, 

 we may fairly presume their eggs are more generally dispersed, and 

 more readily developed. On the other hand, the llotatoria, and 

 more beautiful species of Polygmtrica, ai'e confined to localities more 

 open to the fi'esh air. Ehi'enberg, for man)' years, has experimented 

 with simple spring water, with distilled water, and rain water, and 

 these, both boiled and cold, as also with and without vegetable 

 matter ; that in open vessels, after a longer or shorter time, depend- 

 ing upon temperatui-e and other cii'cumstances, he invariably found 

 tlie Infusoria ; while, in closed vessels, they were rarely to be met 

 with ; so that it seems, we may consider getieratio aquivoea, even in 

 Infusoria, as an unphilosophical hypothesis ; and that the same fixed 

 laws of Creative Wisdom, which regulate and govern the smallest 

 satellite and the largest stany world through boundless space, has 

 established the same law for the development of a living atom, as is 

 manifested to us in the largest animal that inhabits this planet. 



On this subject we may refer the reader to the often quoted ex- 

 periment of M. Schultz, ■\\'ho contrived an apparatus to prevent the 

 introduction of any living germs, by the atmosphere, in a portion of 

 water experimented on. This experiment has generally been viewed 

 as decisive against the doctrine of spontaneous generation. It is 

 thus recorded: — "1 filled, (says Schultz) a glass flask, half full of 



